United Kingdom, May 11 -- Sienna Miller has given birth to her third child.

The 44-year-old actress - who has Marlowe, 13, with former partner Tom Sturridge and a two-year-old daughter whose name hasn't been publicly revealed with boyfriend Oli Green - announced late last year that she was expecting another baby and while promoting her latest project, Jack Ryan: Ghost War, she revealed she has welcomed the tot into the world, though she didn't give any further details about the baby.

She told E! News: "It's happened. I have a tiny baby next door.

"It feels like stringing sentences together is a bit challenging.

"I'm on very little sleep but I'm madly in love with my baby."

In Jack Ryan: Ghost War, Sienna plays MI6 officer Emma Marlow...